For the manufacture of composites, it is often required to move layments (uncured laminated charges) through various operations and locations. The layments have features, often on the bottom side, and therefore not visible, requiring precise location or registration to produce the finished product. In known processes, maintaining the registration through the laminate processing is complicated by the lack of stable, locatable features present on the layments.
It is important to maintain positional registration of composite layments, especially when the layment is assembled on a temporary surface other than a cure mandrel. As a result, there are several sources of potential error relative to the incorrect positioning of layments. For example, layment edges are often subject to the tolerance of cutting plies “on the fly”. Further, layment edges are subject to distortion due to subsequent forming operations, and layment edges may be covered by subsequent layers or splices. If crenulated edges are formed on the layment (such as, for example, when individual tapes are square cut leaving a saw tooth edge), such edges are poor for subsequent accurate orientation.
Known layment-orienting solutions consist of external markings, such as, for example, those applied with an ink jet device. However, such markings are temporary, imprecise and have poor machine readability. Such markings are often further unreadable under bagging material, and are further inaccessible (not readable) from the opposite side of the layment. Tooling holes have sometimes been used to orient or register metal parts, but this technique is of little use with uncured laminates.